Imagine a scenario where the Withdrawal Agreement, as it currently stands, (the one which the House of Commons has rejected by 230 votes), is signed, and following a Transition Period, the UK and EU have failed to reach a Trade Agreement.

The following may be an over-simplification but broadly I understand the position to be that a "backstop" then applies so as to keep the whole of the UK in the Customs Union, and in addition Northern Ireland in the Single Market.

Now, it is frequently complained both by right-wing Conservatives, and members of the Labour Party, that Britain would not be able to "exit the backstop".But what exactly would it mean "to exit the backstop"?

Where is it envisaged Britain would be "exiting the backstop" to go? Presumably not back to EU membership. "Exiting" can only mean going to "no-deal" involving WTO terms, and a hard border in Ireland.

So is it the case that Britain would simply not be able to abrogate the agreement? If that is the case, surely it is unusual for there to be an international agreement, which one party, subject to giving proper notice, is not able to leave. Are there any other examples of such concluded agreements?

Or is it simply being said that Britain could not "exit the backstop" while keeping an open border with Ireland?

  • The Hard Brexit wing of Parliament believe that the Backstop will actually prevent a "good" trade deal being negotiated with the EU. They believe the Backstop solves all the EU's problems and the EU will be happy to leave the UK in a no-mans land, between in and out.
    – Jontia
    Commented Jan 31, 2019 at 9:14
  • @Jontia Yes. That much I am clear about. But what is meant when it is claimed Britain could not leave the backstop? Surely if we were prepared for "no deal" and a hard Irish border we could, couldn't we?
    – WS2
    Commented Jan 31, 2019 at 9:42
  • then you probably want to look at this Question. politics.stackexchange.com/questions/35347/… for why the UK could not leave the backstop. And maybe this one, but there are loads of others politics.stackexchange.com/questions/24475/… for the problems with having a Hard Irish border, which it is worth noting both the EU and the UK say they don't want. It's one of TM's "Red Lines".
    – Jontia
    Commented Jan 31, 2019 at 10:47
  • If there is a backstop at all, it will be because both the UK and the EU has agreed to it. Currently the EU are indicating they won't agree to any agreement which has provisions for the UK unilaterally leaving the customs union.
    – Caleth
    Commented Jan 31, 2019 at 12:48
  • @Caleth See my comment below, to outflak.
    – WS2
    Commented Jan 31, 2019 at 13:26

2 Answers 2


The backstop kicks in if the UK and EU have not agreed a way to keep the Irish border open by the end of the transition period, which is currently December 31st 2020.

If that happens then the backstop keeps the entire UK in the EU's customs union, meaning that the UK must enforce EU customs rules at all borders and thus there is no need for an EU/UK border in Ireland. It would also be of great benefit to the UK as it would keep all other ports serving the EU free from checks as well.

However, inside the customs union the UK would find it very hard to do trade deals with other countries because it would be required to stick to EU rules. Say for example the US wanted to make accepting its meat products a condition of doing a wider deal, as seems likely, those products do no meet EU standards and the UK could not agree to that.

Leaving the backstop would mean that the UK abandons EU customs union rules. That creates a problem in Ireland, as both the EU and UK are obliged to maintain a border there under WTO rules in the absence of any other deals. Any infrastructure or limits on movement across the border may also result in a return to sectarian violence.

Both the UK and EU have ruled this outcome out, but some in the UK want to make it an option again because they fear being "trapped" in the backstop forever. Currently the EU must approve any plan to leave the backstop, ensuring that it won't result in a hard border in Ireland.

  • So, even if Britain were prepared to accept the idea of a hard Irish border, are you saying that we would still not be able to come out of the backstop? If that is the case then it does seem illogical, since if we simply crash out on 29 March this year, we will effectively be doing the same thing. And the EU does not appear to be using the terms of the Good Friday agreement to stop us doing that.
    – WS2
    Commented Jan 31, 2019 at 10:12
  • 1
    @ouflak the EU is a party to the GFA in that it is based on EU treaties providing for things like a customs union, freedom of movement and other relevant rights. If those go away then the GFA collapses. Also the EU was involved in forming the agreement, even thought it was not a signatory (and why would it be in an agreement between two member states?)
    – user
    Commented Jan 31, 2019 at 12:39
  • 2
    @ouflak I don't see how the UK can say they will "never put up a hard border". If we end up with tariffs between the EU and Britain, as seems inevitable, without an agreement, Britain will want to collect the duty on imports from Ireland into the north. Whilst things like VAT, tax etc can exist under separate governments without any border, I fail to see how you can be assured of collecting all your tariff dues without one.
    – WS2
    Commented Jan 31, 2019 at 13:08
  • 1
    @outflak Ireland is not establishing any kind of land border. They are preparing their ports to handle boats arriving from the UK though. Should the worst happen it would likely be resolved by international legal action and WTO complaints.
    – user
    Commented Jan 31, 2019 at 14:40
  • 1
    @ouflak "drafting plans" is not "in the early stages of putting up a hard border".
    – user
    Commented Jan 31, 2019 at 15:41

Exiting the backstop would entail establishing a customs border between EU and UK that will control the passage of goods between the separate markets of the EU and the UK governed by different trade treaties, different taxation and tariff regimes, and different regulations with regard of permissable and prohibited goods.

Putting this between Northern Ireland and Ireland would rekindle the pre-EU conflicts there, putting it in the Irish sea was opposed by DUP, part of the current government coalition. Putting it nowhere would fuel great trade treaties with the U.S. and other parties because of providing unfettered access to EU markets. Which makes this option unrealistic to be accepted by the EU.

In a way, the Backstop may be viewed as a "let's wait until the DUP is no longer in power until doing Brexit proper" regulation, active for an indefinite amount of time. Today's votes against both a mandate for a No Deal Brexit as a bargaining chip as well as a general election have closed two ways in which Johnson might have achieved a deal in opposition to the DUP's terms once either his mandate had become irrevocable for dictating the kind of deal the EU could get as an alternative to none at all, or he'd at least have had the chance to lead a different government without DUP participation.

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